Telephone-exchange system.



A. 'E. 'LUNDELL- TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED JUNE I7. 1916.

Patented 001;; 2 ,1917.

4 SHEETS-SHEET 1.

'l A E.-LUNDELL. TELEPHONE EXCHANGE SYSTEM.

- APPLICATION'FILED1UNE17,19I6.

Patented. 06m. 2, 1917.

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TELEPHONE EXCHANGE SYSTEM.

APPUCATION FILED JUNE I7. I916.

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A. E. LUNDEL L. TELEPHONE EXCHANGE SYSTEM.

-APPLICAT|0N FILED JUNE 17. I916.

Patented Oct. 2, 1917.

4 SHEETSSHEET 4.

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ALBEN E. LUNDEIQL, on NEW YoRK, N. Y., ASSIGNOR To WEsTERN ELECTRIC COMPANY,

INCORPORATED, on NEW YoRK, N.'Y., A CORPORATION on NEW YoRK.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

Application filed June 17, 1916. Serial No. 104,230.

To all whom it may concern Be it known that I, ALBEN E. LUNDELL,

a citizen of the United States, residing at New York, in the county of Bronx and State or" New York, have invented certain new and useful Improvements in Telephone- EX- change Systems, of which the following is a :full, clear, concise, and exact description.

This invention relates to telephone exchange systems, and more particularly to controlling arrangements for semi-automatic telephone exchanges.

It is the object of this invention to do away with the complicated relay arrangements adapted to control the starting and releasing of selector switches in semi-automatic telephone exchange systems.

With this object in view, according to the main feature of the invention, the controlling operator is provided with two keys, one controlling the starting or assignment and another one the releasing of a selector switch, these keys being adapted to mechani-- cally control the actuation of each other.

The drawin s represent a semi-automatic telephone exchange system,only so much being shown of the circuits and apparatus employed in the building up of a connection as is necessary for a clear understanding of the invention. The complete description of the controlling apparatus. and the selector switches controlled thereby may be had from Patent 1,168,319, of January 18, 1916, to

A. E. Lundell. Figure 1 indicates a calling 1 subscribers station and an A operators cord circuit. Fig. 2 (to be placed to the right of Fig. 1) represents a B or controlling operators connecting circuit, and the circuits of a selector switch; Fig. 3 (to be placed to the right of Fig. 2) represents the circuit ar rangement of a connector switch; and Fig. 4 (to be placed below Fig. 2) represents the controlling apparatus of the B operator.

A subscriber at station 100, desiring to obtain connection to a subscriber at station 300, removes his receiver from the switchhook, whereupon a line relay LR becomes energized, and causes the lighting of a calling lamp CL. The A operator, noticing the lighting of lamp CL, inserts a plug 101 into a jack 102, in which the calling subscribers line terminates, whereupon a circuit is established from ground, through the winding of a cut-ofl? relay CO, the sleeve contacts of jack 102 and plug 101, a resistance 103, the

subscriber by actuating her listening-key 105. Supposing that the called subscribers line terminates in another oflice,,the A operator actuates a key 106, thus connecting her head-set through a call circuit 10'? to a 'B operators telephone head-set 200. The A operator, after having transmitted the instructions of the calling subscriber to the B operator, inserts plug 108 into a j ack109, in which a trunk 1101l1, assigned by the B operator, terminates, whereupon a circuit is closed from grounded battery through the left-hand winding of a relay 201, the pri mary winding of a repeating coil 202, trunk conductor 110, the tip contacts of jack 109] v and plug 108, and thesecondary winding of a repeating coil 112 to ground. Relay 201. becomes energized. TheB operator depresses now her start or assignment key 203, causing a key-locking bar 204to move against the tension of a coiled spring 205. When an opening 206 of the locking-bar 204 is opposite a shoulder 207 of a disconnect key 208, this key moves under the control of a coiled spring. 209, into the same position in which key 203 is represented in the drawing. Key 203is moved against the tension of a coiled spring 210 and is locked. by bar'204 in the position noted that the locking of key 203 is not absorammed oer. 2, 1917..

'90 indicated at key 207 in the drawing. It is:

lutely essential. .Key 203 closes a contact 211, and. ground is connected through a contact 212 and the power magnet of a sequence switch 213 to grounded battery. Sequence switch 213 moves intoposition 2, and closes a circuit from ground through its contact 214, conductor 215, a contact 400 of sequence switch 401, and the winding of a relay 402 to grounded battery. Relay 402 closes a circuit from ground through its left-hand armature and front contact, a contact 403 and the power magnet of sequence switch 401 to grounded battery, whereupon this sequence switch is moved out of position 1 into position 3. Relay402 remains energized, due to the closure of a circuit from grounded battery, through the winding of this relay,-

sequence switch contact 404, the right-hand front contact and armature of relay 402, conductor 405, and sequence switch contact 216 to ground.

The B operator actuates her keyboard in accordance with instructions received from the A operator. Only two rows of keys are shown in the drawings (Fig. 4) although it is well understood that a plurality of rows of such keys are provided in practice. Supposing that the called subscribers line may be reached by causing selector switch 220 and connector 301 to take ten steps, the operator depresses a key 406 for controlling selector 220 and a key 40? for controlling connector 301. She then actuatesastart key 408, whereupon a circuit is established from ground through contact of starting key 408', a contact 409 and the power magnet of sequence switch 401 to grounded battery. Sequence switch 401 moves out of position 3 into position 4. A fundamental circuit is closed now from grounded battery through the winding of a relay 221, sequence switch contact 222, conductor 223, sequence switch contact 410, the outer armature and back contact of the upper counting relay 0, and the windings of a stepping relay 41.1 to ground. Relays 221 and 411 become energized. Relay 221 closes a circuit from ground, through its right-hand armature and front contact, and a contact 224 and the power magnet of sequence switch 213 to grounded battery, whereupon this sequence switch is moved into position 3. The relay 221 remains energized, due to the closure of a locking circuit from grounded battery through the winding, left-hand front contact and armature of this relay, and a sequence switch contact 225. In position 3 of sequence switch 213, a circuit is closed from grounded battery through the winding of a magnet 226, sequence switch contacts 227 and 223, and the right-hand front contact and armature of relay 221 to ground. Magnet 226 attracts its armature 229 and presses thus a brush rod 230 against a roller 231 constantly rotating in the direction indicated by the arrow. The brush rod with wlp' 232, 233 and 234, and the commutator brush 235, is caused to move in an upward direction, the wipers 232, 233 and 234 engaging terminals of the bank 236, and the brush 235, conducting segments 23?, and insulated segments 238 of a commutator plate 239.

Upon the energization of magnet 411, a circuit is closed from ground through the front contact and armature of this magnet, a sequence switch contact 412, conductor 413, the contact of key 406, conductor 414, the armature and back contact of the upper counting relay 9, and the winding of the lower counting relay 9' to grounded battery. The lower counting relay 9 becomes ener gi'zed and closes a circuit from. groundthrough a sequence switch contact 415, conductor 416, the armatureand front contact of the lower counting relay 9, and the wind ings of the upper and lower counting relays 9 to grounded battery. The upper counting relay cannot become energized, due to the fact that its winding is short-circuited by the circuit to ground at the armature and front contact of relay 411. As soon as commutator brush reaches a conducting segment 237, ground is connected through brush 235, conducting segment 237, conductor 240, sequence switch contacts 241, and 225 to relay 221, thus shunting out relay 411. The stepping relay, being shortcircuited, releases its armature, thus removing the short circuit from the winding of the upper counting relay 9. This relay becomes energized and extends conductor 414 through the armature and back contact of the upper counting relay 8, and the winding of the lower counting relay 3 to grounded battery. The lower counting relay 8 becomes energized and connects ground to the winding of the upper counting relay 3. This relay, however, does not become energized, due to the fact that in the meantime brush 235 reached the first insulated segment 233 and removed "hus the short circuit from the winding of the stepping relay 411, which, in turn, short-circuited the upper counting relay 8. The operation of the counting relays continues in the same manner until the upper counting relay 0 becomes ener ized. This relay opens the fundamental circuit at its outer armature, causing thus the dcener ization of relays 411 and 221. The upper counting relay closes a circuit from ground through sequence switch contact 417, the inner armature and front contact of upper counting relay 0, and the power magnet of sequence switch 401 to grounded battery, for moving this sequence switch into position 6. lVhen contact 415 is opened, the counting relays release their armatures.

Upon the deenergization of relay 221, a circuit is closed from ground through the right-hand armature and back contact of this relay, a sequence switch contact and the power magnet of sequence switch 213 to grounded battery. Sequence switch 213 moves into position 8. "When sequence switch 213 left position 3, the circuit of magnet 226 was opened at contacts 227 and 228, and the wipers were arrested in engagement with trunk conductors 302, 303 and 304. The testing of this trunk is ac complished in the well-known manner in position 8 of the sequence switch 213, a circuit being closed from grounded battery through the winding of a relay 305, test conductor 304, wiper 234, and sequence switch contact 243 to ground. Relay 305ibe comes energized.

Sequence switch 401 reached in the meantime positlon 6, and a circuit is established from grounded battery through the winding of relay 221, contact 222, conductor 223, sequence switch contact 410, the outer armature and back contact of the upper counting relay 0, and the windings of stepping relay 411 to ground. Relays 221 and 411 grounded battery through the winding of the relay 306, sequence switch contact 307, trunk conductor 302, wiper 232, sequence switch contacts 245 and 228 and the righthand front contact and armature of'relay 221 to ground. Relay 306 becomes energized and closes a circuit from ground, through its right-hand armature and front contact,

a contact 308 and the power magnet of the sequence switch 309 to grounded battery.

Sequence switch 309 moves into position 5 2, in which position a circuit is closed from grounded battery through the winding of clutch magnet 310, sequence switch contact 311, and the right-hand front contact and armature of relay 306 to ground. Magnet 310 causes the upward movement of wipers 312,313 and 314 and brush 315 in. the same manner as magnet 226 caused the movement of the wipers and brushes'of selector 220. Relay 411 closes a circuit from ground through its front contact and armature, sequence switch contact 420, conductor 421 and. the contact of key 407 for the counting relays, and these relays are operated in the same manner as above described, the shortcircuiting of stepping relay 411 being controlled by a circuit extending from ground through brush 315, the conducting segments of commutator plate 316, conductor 317, sequence switch contact 318, trunk conductor 303, selector brush 233, sequence switch contact 246, to relay 221. When the upper counting relay 0 becomes energized, relays 411, 221 and 306 become deenergized, and sequence switch 401 is moved out of posi tion 6 into position 16, from which position it is driven into its normal position by circuit closed from ground through the lefthand armature and back contact of relay 402, which in the meantime became deenergized, and a contact 422 and the power magnet of the sequence switch to grounded battery. Upon the denergization of relay 306, a circuit is closed from ground through the armature and back contact'of this relay, a contact 319 and the power magnet of sequence switch 309 to grounded battery, for

moving the sequence switch out of position 2 into position 16. When sequence'switch 309 leaves position 2, the 'circuit of the driv-- ing magnet 310 is opened and the connector is arrested with its wipers on the-terminalsof the called line. "The testing of the called line is accomplished in the well-known 11121111".

ner through a test circuit extending from grounded battery through the winding ofa cut-offrelay-CO, wiper 314 and sequence switch contact 320. to ground. Re-

lay 221, upon deenergization, closes a circu1t from ground through its rlght-hand armature and back contact, the contact .242

andthe power magnet of sequence switch 213 to grounded battery, whereupon the sequence switch is moved into position 16.

so i

A circuit is now closed from ground through the armature and front contact of relay 201, sequence switch contact 250, the winding of ringing relay 251, armature and back contact of relay 252,-armatureand back contact of relay 253 to grounded battery. Ringing relay 251 becomes energized; relay 252 is short-circuited through the contacts of the ringing cut-off relay 253 and relay 252. Relay 251, closes a ringing circuit through its upper and lower armatures, ringing current being supplied from a generator 254. When the )called Jsubscriber removes his receiver from the 'switchhook, the marginal ringing relay 253 becomes energized and opens the short circuit which exists around the winding of relay 252.

Relay 252 becomes energized and closes a locking circuitfor itself (from grounded battery through the winding, left-hand armature and front contact of relay 252, sequence switch contact 250, front contact and armature of relay 201 to ground) and short-circuits the ringing relay 251, which becomes deenergized. Upon the removal of the receiver at the called station, a supervisory relay 255 becomes energized in the well-known manner and closes a circuit from ground through its armature and the right-hand winding of relay 201 for a supervi sory relay SR at the A operators position.

When disconnection is desired, the called subscribed restores his receiver to the switch hook, thus causing the deenergization'of relay 255 which, in turn, opens the circuit of the supervisory relay SR. This supervisory relay removes the shunt from around lamp SL, and when the calling subscriber causes the deenergization of supervisory relay SR and thus the lighting of lamp SL, the A operator removes plugs 101 and 108 from their respective jacks, whereupon relays GO and 201 become deenergized. Relay 201. closes a circuit from. ground through its arnnrturc and back contact, a sequence switch contact 256, and lamp- 257 to ground ed battery. The B operatonnoticing the lamp 256 lighted, depresses her disconnect 1 key, whereupon the keys 203 and 208 move magnet, the brush rod is moved in a downward direction, and during the movement of the brush rod, a lamp 262 is lighted. vVhen brush 235 reaches its normal conducting plate 263, a circuit-is closed from ground, through brush 235, plate 263, a contact 26% and the power magnet of sequence switch 213 to grounded battery, for moving this sequence switch out of position 18 into position 1', whereupon the circuit of magnet 260 is opened. Relay 252 becomes deenergized and lamp 262 extinguished.

When wiper 23 1 disengages the terminal of conductor 30%, relay 305 becomes deenergized and closes a circuit from ground through its armature and back contact, a contact and the power magnet of sequence switch 309' for driving this switch int-0 position 18. A circuit is now closed from grounded battery through the winding of magnet 326 and a sequence switch conta'ct'327 to ground, and this magnet causes the connector brush rod to move in a downward direction. When the brush rod is restored to normal, a circuit is closed from ground through commutator brush 315, a conducting plate 328, a contact 329 and the power magnet of sequence switch 309 to grounded battery, Sequence switch 309 is moved into position 1 and magnet 326 b comes deenergized.

\Vhat is claimed is: r

1. In a telephone exchange system, a calling and a called line, a selector switch adapted to interconnect the same, OPGL'QJt. ing and releasing means for said selector, a manually control-led device for actuating said operating means, another manually controlled device for actuating the releasing means, av mechanical locking means adapted to engage one of said devlces, and means operated by the other "device for actuating said locking means. I

2. In a telephone exchange system, a plurality of lines, a selector switch for interconnecting two of said lines, controllin anparatus for said selector switch, a key for starting and another key for releasing said; controlling apparatus, and a single mechanical locking means for said keys adapted to be actuated by either one of said keys.

3. In a telephone exchange system, a plurality of lines, a selector switch for interconnecting two of said lines, a sequence switch for controlling the operation of said selector switch, a key for starting and another key for releasing said sequence switch, a bar adapted to lock said second mentioned key in its operating position, and means operable uponv the actuation of said first mentioned key for releasing said bar.

111 witness whereof, I hereunto subscribe my name this 15 day of June, A. D.-, 1916.

ALBEN E. LUNDELL.

Copies of this patent may be obtained for fivecents each, by addressing the Commissioner of Patents.

Washington, 11 C. 

